Electromagnetic Effects on Plasma Resonance Cones

The electromagnetic modifications to the electrostatic theory of plasma resonance cones are presented for frequencies sufficiently high to allow the neglect of ion motion. The amplitude of the potential near the resonance cone is studied numerically and analytically when electromagnetic effects can be considered to be a small correction. The most important effects are a reduction in amplitude and an angular shift of the main peak and interference structure. The conditions under which these effects are important are derived.